Sewing machine upper feed control



June 29, 1965 K. NlcoLAY SEWING MACHINE UPPER FEED CONTROL 6 Sheets-Sheet 1 Filed March 18, 1963 /NrfA/rap June 29, 1965 K. NICOLAY SEWING MACHINE UPPER FEED CONTROL Filed March 18, 1965 6 Sheets-Sheet 2 @Mdm June 29, 1965 K. NlcoLAY 3,191,551

SEWING MACHINE UPPER FEED CONTROL Filed latch 18, 1963 6 Sheets-Sheet 3 me; /VlcoLN/l June 29, 1965 mNmoL/.w

SEWING; MACHINE.. UPER'` FEED G QNTROL.;

65 SheeiSPShQBf, 41

Filed March 18, 19.633

June 29, 1965 K. NlcoLAY SEWING MACHINE UPPER FEED CONTROL 6 Sheets-Sheet 5 Filed March 18. 1963 r I: mi

June 29, 1965 l K. NlcoLAY 3,191,551

SEWING MACHINE UPPER FEED CONTROL Filed March 18. 1963 6 Sheets-Sheet 6 MWF/vra(D MRL l COLA);

om im United States Patent O 7 Claims. (Cr. 112-212) This invention relates to a sewing machine of the kind in which the work feeding devices, include an upper feeder foot which is raised from lthe workpiece alternately with a presser foot, and the invention relates in particular to a control means for varying the lift stroke of these alternately operating feet, during the running of the machine. t

It is known that the lift stroke to be given to the upper feeder member and to the pressed foot depends at any given time on .the thickest place of vthe piece of material to be sewn for example sea-ms or .the like which are to be stitched across. The higher the foot stroke must be, in order to sew over these thick places, the more the material feeder device when driven at high speed, tends to flutter and this reduces the output of the sewing machine in that the maximum sewing speed must 4be kept sufficiently low :to avoid this risk. Because of the thicker places in the sewing path, this limitation means therefore has meant that the necessary lifting stroke for overcoming the .thicker places determines the sewing machine speed for the whole sewing operation.

' In order to combat this loutput reducing fault, it is proposed according to the present invention to make the foot stroke of the alternately working feet variable during the running of .the sewing machine by an adjustment means which is controllable for this purpose either directly or indirectly. Thereby it is attained that even thick material can be fed with comparatively small foot stroke at high sewing speed, and thicker places yto be crossed by the stitching are climbed over by the alternating feeder and presser feet with a larger lifting stroke.

For varying the foot stroke of the feeder and presser feet various controls are proposed according to the invention which render it possible to control suitably the driving mechanism of .the feed during the running of the sewing machine, lby directly or indirectly influenced adjusting means.

Thus, for the purpose of the direct influencing of the lifting stroke of these feet, control means are provided which act directly on the means for the adjusting of the lifting stroke and are made eifective by operation of a foot lever or .the like means actuated at the instance of the operator.

For the indirect influencing of the lift stroke of the alternating feet, a control device inuenced automatically by centrifugal force may be employed, reacting suitably on variation of lthe speed of rotation of the machine at the time.

Furthermore, according to the invention there may be provided :an indirectly effective control means for the adjusting of the lifting stroke which is in communication with the regulating device for controlling the drive to the sewing machine.

The invention will now be described with reference to the accompanying drawings, wherein:

iFIG. l shows a vertical section through theupper part of a sewing ma-chine with a feeder foot lifting from the workpiece alternately with the presser foot and a control device working indirectly according to the invention;

FIG. 2 shows a part-sectional front end view of the upper part of the same sewing machine;

FIG. 3 is a section of a portion of the upper par-t of the machine showing the drive of the work-feeding device and control elements for direct control;

3,191,561 Patented June 29, 1965 ice FIG. 4 shows va similar view but with the drive of the work-feeding device and control elements for indirect control;

FIG. 5 is a sectional transverse view of parts for the control of the drive of the work-feeding device;

FIG. 6 .shows a sewing table arrangement for direct control of the feeding device;

FIG. 7 shows a sewing table arrangement for indirect control of the feeding device;

fFIG. 8 is a section through the part of the sewing machines, with a view of the control member, and;

FIG. 9 is an exploded view of a centrifugal governor.

As shown the improved sewing machine carries in bearings 1, 2 and 3 (-FIG. 1) of the upper part 4 a rotating arm shaft 5. The drive of the sewing machine is effected in the usual manner from a motor 6 '(FIG. 6) via a clutch.

device 6a and a driving pulley 7 on the said arm shaft `5. Besides the known driving mechanism for the movements of the needle bar 8, which carries a sewing needle 9 and which moves with the advance of the workpiece, the arm shaft 5 drives a parallel shaft 13 held in bearings 10, 11 and 12 (FIG. 3) of the upper part 4, the drive being via a driving gear 14 and a timing belt 15 so that the shaft 13 rotates at the same speed as the arm shaft 5.`

The shaft 13 serves for actuating means for the driving of an upper work-feeding device, the foot 16 (FIG. 2)

of which is raised and lowered alternately with a presser foot 17 of the sewing machine, relatively to the work material being fed below the needle. For producing the lifting and `pressing movement of the feeding and presser feet 16, 17 there is used what i-s the equivalent of two bent levers, namely a triangular lever 18 and a cornpression spring guide rod 19. Hereby the spring guide rod 19 serves as the one arm of each of the two lbent. levers and is linked in a joint 20 of the triangula-r lever 18. The virtual arms 21, 22 of the triangular lever 18 lead from the joint 2t) to links 23 :and 24 and thereby to the .pressure foot 16 and to the feeder foot 17. The link 23 connects the triangular lever 18 to the presser foot bar 25 with-in the upper part 4 of the machine.

For the connection of the triangular lever 18 to the feeder foot bar 26 a link 27 is used so that such bar 26, mounted in a needle pivot frame 28 can participate with the feeder foot 17 in the advancing movement of the lower feeder beneath the needle plate. For the resilient pressure of the feeder and presser feet 17 and 16 the triangular lever arrangement is sprung by means of a com-` pression spring 29 carried on the spring guide rod 19. Wi-th its upper end 30 the spring guide rod 19 is axially movable through a bearing 31 located in the upper part 4 of the machine and pivotally mounted to accommodate the movements of the triangular lever 18. Thereby the compression spring 29 is supported on the lower edge 33 of an adjusting screw 34 mounted in the bearing 31 and, according to the screwing-in depth of screw 34, acts on the triangular lever arrangement via the pressure ring 355, which lies between the bottom end of the spring and the upper joint 20 of the lever 18 where it receives the spring guide rod 19, that is, the compression spring 29 presses down both the feeder and presser feet 17 and 16, into the respective working positions on the material being sewn.

As a driving means for the operation of the upper feeder arrangement there is used, for example, an oblique cam 36 (FIG. 3) which, for the purpose of adjustment of its magnitude of lift, ismovable on theshaft 13. Around the eccentric part of the oblique cam 36 there is placed an eccentric ring 38 which is so held by means of a pin 38 that the oblique cam 36 can be moved in a functional manner in the bore of the eccentric ring 38 for the adjust-V ment of the stroke. For the operation of the triangular lever arrangement, an eccentric strap 37 is used. This provides the connection to a link transmission which is composed of a double-armed lever 39 (FIG. 2) mounted in the upper part 4 of the machine and an in-termediate member 46 the end of which is articularly connected to the triangular lever 1S on the free end of the pivot bolt 41 which is fixedly carried by that lever.

For the control of the oblique cam 36 (FIG. 3), for the purpose of thev adjustment of the necessary lifting stroke, the invention provides means which are effective either directly or indirectly.

For the direct control of the cam 36, there is provided a fork lever 43 (FIG. 5) which can swing around a bolt 42 mounted in the upper part 4 of the machine. With its arms 44 and 45 which engage around the hub 45a of the oblique cam 36, it carries slide blocks 45h which enter into an annular groove 36a of the oblique cam 36 to effect the sliding movement along the shaft 13.

A control transmission comprising parts 46, 47, 48, 49, 50 and 51 connects the arm 45 of the lever 43 to a foot pedal 52 (FIG. 6) which is independent of a foot pedal 73 for the operation of the normal clutch of the driving motor of the machine. Upon operation of the pedal 52 the fork lever 43, normally held by the spring 53 against a fixed stop 54 (FIG. 3) in the upper part 4, can be pivoted against the pull of the spring 53, and thereby move the oblique cam 36 through the ring 33 for the adjustment of the lifting stroke of the alternating feeder foot 16 and presser foot 17, during the running of the sewing machine. According to the construction of the oblique cam 36, an adjustment from small to ylarge lift stroke or vice versa can be effected.

' For the indirect control of the lifting stroke, a centrifugal governor is proposed which is arranged on the shaft 13 and operates in dependence on the rotational speed transmitted to this shaft. The centrifugal governor includes a part 55 (FIG. 9) which is rmly screwed on the shaft 13 by screws 55. The part 55 carries in opposite grooves 56, 57 centrifugal weight levers 6i) and 61, guided pivotally on bolts 53, 59. These centrifugal weight levers are drawn together by traction springs 62, 63 acting between holding means 72 and '72', so that rollers 66 and 67 rotatably mounted on bolts 64 and 65 on the end of the levers 66, 61 lie on the shaft 13, when the governor is in the neutral position.

For its control by the centrifugal governor the oblique cam 68, movably located on the shaft 13, is provided interiorly with anl ascending curved path 69 (FIG. 4). Traction springs 70, 71, fixed at one end on the part 55 and at the other end on the oblique cam 68, draw such curved path 69 towards the rollers 66 and 67 of the oentrifugal weight levers 60 and 61 so that when the centrifugal force is effective the rollers 66 and 67 separate and roll on the curved path 69 as the cam is pulled axially by the springs 76, '71, in dependence on the rotational speed of the shaft 13, and thereby the lifting stroke of the alternating feet 16 and 17 is varied indirectly in dependence on the speed of operation of the sewing machine.

A likewise indirectly effective control of the lifting stroke for the feet 16 and 17 is attained if the oblique cam 36 (FIG. 3) is adjusted by means which operate in dependence on the speed regulating devices i-n the drive of the sewing machine. This can be attained in a simple manner if the oblique cam 36 (FIG. 3) as inthe irstdescribed direct control arrangement is linked by the fork lever V43, and the control members 46, 47, 48, 50 and 51 (FIGS. 3, 8 and 7) not now into connection with theV foot pedal 52 (FIG. 6) but with the foot pedal 73V (FIG. 7) which serves for the operation of the clutch of the motor 6. Thereby, the lifting stroke of the feet 16 and 17 can be automatically controlled in dependence on the regulation of the drive of the sewing machine. Direct or indirect control, that is, control dependent on or independi ent of the speed of operation of the sewing machine can be attained in this manner with small expenditure.

What I claim ris:

1. In a sewing machine, in combination with a presser foot having a lifting bar, an upper feeder foot having a lifting bar and means for lifting the feeder foot and the presser foot from a workpiece alternatively, a control device for varying the extent of lift of said presser foot and feeder foot comprising a lever having three pivot points in a substantially triangular arrangement, a first pivot connection between one of said pivot points of said lever and said presser foot lifting bar, a second pivot connection between a second point of said lever and said feeder foot lifting bar, spring' means bearing upon and urging movement of said three point lever to depress the said lifting bars, a drive shaft, an oblique cam supported on said drive shaft for sliding movement thereon and connected thereto for rotation therewith, an eccentric fixed to said drive shaft and translixed rotatably by said oblique cam, an eccentric strap' on said eccentric, a rocker arm, a pivotal coupling between an end of said rocker arm and said eccentric strap, a third pivot connection between the third pivot point of said lever and an opposite end of said rocker arm, rotation of said shaft and its oblique cam causing said eccentric and rocker arm to tilt the said lever t0 and fro to raise the said lifting bars alternately, and means for imparting axial movement to the oblique cam to vary the throw of the eccentric and thereby Yvary the lift of said lifting bars.

' 2. The combination according to claim 1, wherein said oblique cam has an annular groove concentric with said drive shaft, a pivoted fork member engaging in the said groove, a pull rodhaving one end connected to said pivoted fork member, spring means urging said cam and fork member to one end position, an operator-influenced control member, and a linkage mechanism connecting said control member to the other end of said pull rod.

3. The combination according to claim 1, with a pivot block fixed on said drive shaft, Weighted levers pivotally mounted on said block and lying along opposite sides of said drive shaft, spring means urging said levers towards said drive shaft, means forming an annular camming surface on said oblique cam and encircling said shaft and facing toward said block, rollers on said weighted levers engaging the said camming surface, and urging said annular camming surface into engagement with said rollers,

` said weighted levers being movable outwardly under centrifugal force relative to said shaft and forcing said rollers against said annular camming surface and thereby shifting said oblique cam axially against the resistance of said further spring means.

4. The combination according to claim 1, wherein said oblique cam has an annular groove concentric with said drive shaft, a pivoted fork member engaging in the said groove, a pull rod having two ends and,y connected by one of its ends Vto said pivotal fork member, spring means urging said cam and fork member to one end position, a power drive to the sewing machine, a clutch in said power drive, an operator controlled actuating member for said clutch, and a linkage member connecting said actuating member to the other end of said pull rod.

5. In a sewing machine in combination with a presser foot, an upper feeder foot each having a lifting bar and means for lifting said feet from the workpiece alternatively, a control device for varying the extent of such lift comprising a lever having three pivot points disposed in a triangular relation, one pivot point being at the apex of thetriangle and the two pivot points being at the ends of the base of the triangle, a first pivot connection between one base point of the triangle and the lifting bar of the presser foot, a second pivot connection between the other base point of the triangle and the lifting bar of the feeder foot, a vertical guide rode pivotally connected at one end to the lever at the apex of the triangle and supported at its upper end for both vertical sliding movement and rocking movement, a rocker arrn having an end pivotally attached to the lever at a point adjacent to the apex of the triangle, spring means between the upper end support for said rod and the lever at the apex of the latter for depressing the two said lift bars, a drive shaft, an oblique cam supported on said drive shaft for sliding movement thereon and coupled thereto for rotation therewith, an eccentric fixed to said drive shaft, transixed rotatably by said oblique cam, an eccentric strap on said eccentric and pivotally connected to said rocker arm, the rotation of said shaft and its oblique cam causing said eccentric rocker arm to turn said lever on the pivot connecting said guide rod to the lever and eiiecting raising of the said lift bars alternately, and means for imparting sliding movement to said oblique cam to vary the throw of the eccentric and thereby the lift of the said lift bars.

6. The invention according to claim 5, wherein said last means is a centrifugally actuated means carried on and rotating with the shaft and operatively coupled to said oblique cam.

7. The invention according to claim 5, wherein the last means comprises centrifugally actuated weighted levers pivotally attached to said shaft on opposite sides thereof, yieldable means opposing outward swinging movement of the levers by centrifugal force, means forming a camming surface on said oblique cam in opposed relation to said weighted levers, cam follower means carried by said weighted levers engaging said camming surface and applying thrust against the said camming surface and effecting the said sliding movement of the oblique cam, and spring means yieldingly opposing said sliding movement of the oblique cam by centrifugally actuated movement of said weighted levers.

References Cited by the Examiner UNITED STATES PATENTS 1,060,689 5/13 Mack i12-207 2,29 l, 129 7/ 42 Zeier i12-207 FOREIGN PATENTS 688,957 3/53 Great Britain.

JORDAN FRANKLIN, Primary Examiner. 

1. IN A SEWING MACHINE, IN COMBINATION WITH A PRESSER FOOT HAVING A LIFTING BAR, AN UPPER FEED FOOT HAVING A LIFTING BAR AND MEANS FOR LIFTING THE FEEDER FOOT AND THE PRESSER FOOT FROM A WORKPIECE ALTERNATIVELY, A CONTROL DEVICE FOR VARYING THE EXTENT OF THE LIFT OF SAID PRESSER, FOOT AND FEEDER FOOT COMPRISING A LEVER HAVING THREE PIVOT POINTS IN A SUBSTANTIALLY TRIANGULAR ARRANGEMENT, A FIRST PIVOT CONNECTION BETWEEN ONE OF SAID PIVOT POINTS OF SAID LEVER AND SAID PRESSER FOOT LIFTING BAR, A SECOND PIVOT CONNECTION, BETWEEN A SECOND POINT OF SAID LEVER AND SAID FEEDER FOOT LIFTING BAR, SPRING MEANS BEARING UPON AND URGING MOVEMENT OF SAID THREE POINT LEVER TO DEPRESS AND SAID LIFTING BARS, A DRIVE SHAFT, A OBLIQUE CAM SUPPORTED ON SAID DRIVE SHAFT FOR SLIDING MOVEMENT THEREON AND CONNECTED THERETO FOR ROTATION THEREWITH, A ECCENTRIC FIXED TO SAID DRIVE SHAFT AND TRANSFIXED ROTATABLY BY SAID OBLIQUE CAM, AN ECCENTRIC STRAP ON SAID ECCENTRIC, A ROCKER ARM, A PIV- 